This invention relates to rotating electric machines, and in particular to an air gap winding rotating electric machine in which the stator coils can be rigidly and reliably secured to the stator side.
In recent years, air gap winding rotating electric machines have become increasingly common. The main feature of this type of machine is that the stator core has no slots for the disposition of the stator coils. Instead, the stator coils are placed in the space (i.e. the air gap) between the stator core and the rotor. Placing the stator coil windings in the air gap makes efficient use of empty space and increases the magnetic flux density of the stator coils. Their disposition in the air gap is particularly advantageous in large capacity and superconducting rotating electric machines.
However, air gap winding rotating electric machines have the disadvantage that reliably securing the stator coils to the stator core is very difficult. The method used in the prior art of disposing the stator coils in an air gap winding rotating electric machine is to directly bond the stator coils to the stator core using a strong adhesive, such as a resin adhesive. However, a sufficiently strong bond can not be obtained between the stator core and stator coils, and the large forces exerted on the stator coils during operation can result in loosening and unacceptable vibration of the stator coils, damage to the insulation surrounding the coils, and similar problems resulting in machine failure.